Equine Flashcards
What type of breeder is the mare?
Seasonally poyoestrus
Long-day breeders
When is the thoroughbred breeding season?
March through to July
When is a mare in cyclic oestrus in the northern hemisphere?
April to mid-August
What is the main thing that causes the change in seasonal cyclic activity?
Increasing daylight length
What are the three main things that control seasonal cyclic activity?
Reduced melatonin secretion by pineal gland
Reduced GnRH inhibition from hypothalamus
FSH and LH secreted by anterior pituitary gland
Describe how the pineal gland can affect seasonal cyclic activity in the mare
Gland interprets daylight length and regulates melatonin secretion
Melatonin nocturnally produced by pituitary gland
Inhibits Hypothalamic-Pituitary-Ovarian axis
Daylight increases then melatonin level decreases and inhibition of HPO axis downregulated
Leads to GnRH production by hypothalamus
What are some other factors in the mare that can play a role in the transition from anoestrus to normal cycling?
Nutrition
Age
Breed
What is needed for a mare to be able to return to cyclicity?
Large enough quantities of GnRH
Stimulate FSH and LH production by pituitary
What are the three functional seals between the uterus and exterior?
Vulva, cervix and vestibule
What happens to the perineal conformation with age and multiparity?
Abdomen sinks
Anus displaces cranially
Upper commissure of vulva dragged cranially - sloping vulva
What are older, multiparous mares more predisposed to due to their altered perineal conformation?
Pneumovagina
Cervicitis
Endometritis
Describe control of cyclic activity from FSH stimulation to luteinisation
FSH stimulates ovarian follicles
Follicles secrete oestrogen - behaviour change, tract changes, LH stimulation
Follicles secrete inhibin - inhibit FSH secretion
LH stimulates ovulation and luteinisation
Follicle collapses and luteinises - oestrogens and inhibin cease
Describe control of cyclic activity from corpus luteum formation to PGF2alpha secretion
Corpus luteum secretes progesterone - tract changes, behaviour changes
If conception maternal recognition occurs at 14 days post ovulation
Recognition causes blastocyst capsule oestrogens to be produced - prevent endometrial gland secretion of PGF2alpha
No recognition causes endometrial gland secretion of PGF2alpha
Describe control of cyclic activity from PGF2alpha secretion to FSH stimulation
PGF2alpha causes luteolysis of CL
CL stops progesterone secretion
Inhibition of: sexual behaviour, tract changes, LH secretion
Cervix opens
FSH secretion stimulates ovarian follicles
Describe a mares behaviour in oestrus
Submissive Ears forward Legs straddled Tail held high Urinating Everting clitoris
Describe a mare in dioestrus
Violent
Ears back
Screaming
Tail clamped down
Describe the change in each of the 5 hormone levels over one cycle in a mare
Oestrogen - starts to increase day 17, peaks day 3-5, decreases from day 5 until day 10
Progesterone - Increases rapidly from day 5, peaks at day 8 until day 14, drops until day 20
LH - maintains a low base level, increases from day 1, peaks at day 7, rapidly decreases from day 7 until day 12
FSH - maintains low base level, increases from day 3, peak at day 6, drop between days 6 and 8, increases to a higher peak on day 10, decreases on day 10 back to base level on day 14
PGF - maintains a low base level, increases from day 13, peaks at day 15, decreases from day 15 back to base level on day 17
What day of the cycle does ovulation occur?
Day 5
How long is oestrus in the mare?
5 days
Describe hormonal changes during equine pregnancy
Blastocyst capsule secretes oestrogens from day 14
2nd wave of ovarian follicles ovulate and produce progesterone
Chorionic girdle forms endometrial cups which secrete eCG from day 35-100
Foetal gonads secrete oestrone sulphate from day 100-term
What are the four layers of the scrotum?
Skin - sweat glands
Tunica dartos - smooth muscle raises and lowers the testes
Fascia - allows mobility for vertical and lateral movement
Vaginal tunic - abdominal cavity through inguinal canal to bottom of scrotum, watery fluid facilitating movement
What varies in the male horse from month to month?
Testicular function
Semen constituents
Hormone levels
What is the size of mature horse testicles?
80-100mm long
50-80mm wide
225gm weight
When does the pre-pubertal stage in the male horse begin?
Around 6 months of age
What age do most colts actually become able to sexually reproduce?
14 months of age - first age they produce sufficient sperm
What are the 6 stages of spermatogenesis in the horse? How long does it take?
Spermatagonia Preimary spermatocytes Secondary spermatocytes Spherical spermatids Elongated spermatids Spermatazoa
Takes 57 days
Describe the movement of sperm from the seminiferous tubule to ejaculationt
SPerm freed from tubule
Pas into straight tubule and rete testis
Fluid added
Moved through efferent ducts to proximal epididymis
Fluid resorbed in caput epididymis
Sperm matured in corpus epididymis
Sperm stored in cauda epididymis and ampullae
Seminal plasma added by seminal vesicles and prostate
Gel added by seminal vesicles
Ready for ejaculation
What could traumatic injury in the testes result in?
Antisperm autoantibody production
What protects the sperm from the stallion’s immune system?
Sertoli cells - coordinate germ cell differentiation, form blood-testis barrier isolating them from immune system
Describe the spermatic cord in the stallion
Extends from abdominal inguinal ring to testicular attachment
Suspends tests in scrotum
Passage for - ductus deferens, nerves, blood vessels, external cremaster muscle
What produces testosterone in the testis?
Leydig cells
What does the adenohypophysis produce in stallions?
LH
FSH
How does the hypothalamus regulate sexual behaviour in the stallion?
Gonadotrophic releasing hormones
Secreted in short pulsatile bursts in response to neural stimulation
What releases oxytocin and what does it do?
Leydig cells
Facilitates rhythmic contraction of seminiferous tubules
Help evacuate sperm
What do Sertoli cells produce in the stallion? What do they do?
Inhibin and activin
Regulate spermatogenesis
What controls testosterone production in stallions?
LH bursts
How does erection occur?
Penis stiffens and lengthens
Corpus cavernosum engorged first then corpus spongiosum
Initiated by cerebral responses to sexual stimulation
Penile arterioles dilated by parasympathetic over-ride of normal sympathetic control
Blood shunted to fill and disten corpus cavernosum and spongiosum
Penis enlarges
Describe emission in the stallion
Movement and deposition of sperm and fluid
Goes from ductus deferens and cauda epididymis with fluids from accessory glands in the pelvic urethra
Sympathetic impulses control
Describe ejaculation in the stallion
Expulsion of semen through the uretha
Parasympathetic impulses
Series of strong pulsatile contractions - urethralis, bulbospongiosus
5-7 jets of semen
What four things do we need to prepare for in the mare breeding season?
Health - vaccinations, worming, venereal disease screening
Foaling
Pregnant mares
Cycling mares - barren mares, maiden mares, rested mares, recently foaled mares
What does the HBLB codes of practice cover?
Bacterial infections - Taylorella equigenitalis (CEMO), Klebsiella pneumoniae (capsule types 1,2 and 5), Pseudomonas aeruginosa
Viral infections - Equine viral arteritis, equine herpesvirus 1, equine infectious anaemia, equine coital exanthema
Typanasoma equiperdum
Strangles - streptococcus equi
When should pre-season screening be done?
After 1st January and before 15th February
Describe how to swab for bacterial infections in stallions
Tease stallion to penile erection
Stand by stallion’s left shoulder
Penis held with gloved hand
Pre-moistened and pre-labelled normal-tipped swabs passed in order
Where should swabs for bacterial infections be taken? How many times?
Urethral, urethral fossa, prepucial smegma, pre-ejaculatory fluid swabs
2 times seven days apart
What screening is done for viral infections in stallions?
1 serum sample for EVA titre
1 serum sample for EIA test
Vaccinated stallions will be positive
Why are stallions vaccinated against EVA?
Can become carriers
Semen becomes contaminated and mare becomes useless
Freezing and storing does not kill virus in sperm
What swabs are done in mares for pre-season screening?
Late foaling mares swabbed one month before due date
Additional clitoral swabs for dystocia/treated mares - Klebsiella, Pseudomonas
What swabs are taken for bacterial infections in the mare?
1 set clitoral sinus and fossa swabs
What samples are taken for viral infections in the mare?
1 serum sample for EVA titre
1 serum sample for EIA test
What two cultures need to be ruled out in mares with dystocia?
Pseudomonas aeruginosa
Klebsiella pneumoniae
What additional swabs need to be done in mares with dystocia?
Clitoral swab
Endometrial swab
Smear when in oestrus more than 7 days post antibiotic treatment
What should swabs be immersed in and how quickly should they be sent to designated laboratories?
Immersed in Amies charcoal transport medium
Sent no more than 48 hours after collection
What are the clinical signs for bacterial venereal disease?
Vaginal discharge 2 days after mating/AI
No clinical signs
Early return to oestrus - less than 15 days
What should be done if bacterial venereal disease is suspected?
Swab uterus, clitoral fossa and sinuses
Stop mating and AI
Speculum exam
What should be done with bacterial venereal disease?
Improve management of teasing and stud hygiene - prevent stallion sniffing vulva of more than one horse, change gloves between teasing mare, don’t tease genitalia, use disposable equipment
Trace contacts and notify authorities
Treat uterus with appropriate antibiotics
Clitorectomy to remove carrier status
Re-swab 3 times 7 days after treatment
Only mate when negative swab results are confirmed and with agreement of all concerned
What can Equine Viral Arteritis cause?
Brick-red conjunctivitis Fever Depression Filled legs Skin rash Abortion Early pregnancy failure
What should be done if EVA is suspected?
Notifiable disease in UK
Blood samples for antibodies
Nasopharyngeal swabs and tissues for PCR and culture
Stop mating/AI/teasing
Why should we be careful with importing stallions from abroad?
COuld contain endemic diseases from Europe that are not present in the UK
Quarantine and run tests again
DOn’t rely on foreign government tests
What should be done with horses with EVA?
Trace contacts and notify authorities
Follow-up blood samples after 1 month - static titres from same laboratory
Semen cultures - 1/3rd may become permanent shedders, notify DEFRA, castration/euthanasia if positive
Pre-vaccination seronegative test result in passport
6-monthly vaccination of stallions and teasers
No carrier status in mares - safe if static or falling titre
What does equine herpesvirus cause?
Respiratory infection Nasal discharge Abortion risk Ataxia Paralysis Incontinence
Which horses are most at risk of EHV-1?
Weanlings
Yearlings
Horses out of training
What should be done with horses with EHV-1?
Segregate from breeding stock and pregnant mares
Blood samples
Nasopharyngeal swabs
What is the vaccination used for equid herpesvirus?
Equip EHV 1,4 licensed for use against abortion
January and July for all non-pregnant horses
January and July plus 5th, 7th and 9th months of gestation for pregnant mares
What is essential for controlling equid herpesvirus on stud farms?
Geographical organisation
Managing horse cohorting
Management
Biosecurity!
What is equine coital exanthema?
Equivalent to genital herpes
Pox-like lesions appear on penile, puputial, vulval skin 5-9 days
How long is the recovery for equine coital exanthema?
10-14 days
What should be done with equine coital exanthema?
Cease mating
Allow recovery time
Symptomatic treatment
Occasionally recur
Describe equine infectious anaemia
Notifiable in UK
Causes: fever, anaemia, oedema, weight loss, death
Spread by infected horseflies and stableflies
Caused by Lentivirus
How long is a horse with EIA infectious?
Life - put down or kept in solitary
Describe Dourine
Notifiable disease in UK
Trypanasoma equiperdum
Venereal transmission
Four forms
What are the four forms of dourine?
Genital oedema
Skin oedema - silver sickle lesions on skin
Neurological
Wasting disease
Describe strangles
Endemic disease in UK
Respiratory infection - nasal discharge, submandibular abscesses
Internal abscesses - pneumonia, colic, diarrhoea, weight loss
What should be done with a case of suspected strangles?
Discharge swabs
Nasopharyngeal swabs
Isolation of cases and contacts
What is the treatment for strangles?
Contentious
Early - penicillin
Abscesses use hot fomentations - bathing, burst them
What should horses at risk of strangles have done?
Take rectal temperatures twice a day
What should be done with carriers of strangles?
Guttural pouch washes - check clearing
How does blood sampling help with strangles?
Shows challenge with strangles
Can make a decision on whether or not to let the horse onto the stud farm
Can quarantine and guttural pouch wash to check whether clear
What are some good codes of practice in stud farm veterinary practice?
Disease prevention
Advice for: when disease occurs, control, limitation of spread
Standard operating procedures and lines of communication
Education, information and sense of responsibility
Maintenance of integrity of horse breeding industry - individual reputations, studfarm and mare insurance premiums, export trade, individual stallion and mare owner responsibility
DEFRA and insurance considerations
Money well spent
How long is a mares gestation period?
11 months
What day do we want stud mares to begin cyclic oestrus?
15th February
Describe a normal cycling mare in relation to ovaries, cervix, progesterone and advice given
Ovaries - maturing follicles, ovulating follicles
Cervix - pink, moist, relaxed
Progesterone - <1ng/ml
Advice - mate
Describe a mare in anoestrus in relation to ovaries, cervix, progesterone and advice given
Ovaries - small, inactive
Cervix - pale, dry, not shut tight
Progesterone - low, <1ng/ml
Advice - Artificial lighting, time
Describe a mare in the transitional phase in relation to ovaries, cervix, progesterone and advice given
Ovaries - multiple follicles, non-maturing follicles
Cervix - pale, dry, not shut tight
Progesterone - <2ng/ml
Advice - oral allyl trenbolone for 10 days, check 3 days later
Describe a mare in persistent dioestrus in relation to ovaries, cervix, progesterone and advice given
Ovaries - functional CL, variable follicles
Cervix - pale, very dry, shut tight
Progesterone - >2ng/ml
Advice - PGF2alpha intramuscular, look at 2-3 days later
What are the aims in routine mare monitoring?
Maximise fertility
Maximise efficiency of breeding program
Prevent injury and disease
What should we get to know about each mare we monitor?
Cyclic behaviour
Ovarian function
Uterine competence
What hand should we use for palpating when rectalling a horse?
Left hand
Why is record keeping important?
Keep track of information gathered
Describe teasing
Most important way for monitoring cyclic activity Prevent injury to breeding stallion Co-operative, virile pony stallion Need safety for horses and attendants Done Monday, Wednesday and Friday Daily teasing during oestrus From 14 days after last mating Keep records Profile progesterone
Describe mare behaviour during teasing when in oestrus
Submissive Ears forward Legs straddled Tail held high Urinating Everting clitoris
Describe mare behaviour during dioestrus when teasing
Violent
Ears back
Screaming
Tail clamped down
Describe mare behaviour when in the transitional phase
Ambivalent
What should be examined during first show to teaser?
Perineum and vulva
Vaginoscopy - vagina, cervix, endometrial swab, smear tests
Rectal palpation - ovaries, uterus
Ultrasound scan - ovaries, uterus
What does leukocyte present on an endometrial swab mean?
Acute endometritis
What should be looked for in a perineal examination?
Vulval discharge
Injury
Competence
What should be done if discharge is noted on a perineal examination?
Vaginascopic examinations
Swab and smear examinations
Treat
Re-examine at next oestrus
What should be done if injury is noted upon a perineal examination?
Repair
What should be done if incompetence is noted on a perineal examination?
Caslick’s vaginoplasty
Pouret’s perineoplasty surgery
When should problems at first show to teaser should have been treated?
Autumn
Describe what should be seen on a vaginal examination at first show to teaser
Relaxed, pink, moist cervix during oestrus
Tight, pale and dry during dioestrus and pregnancy
What two samples should be taken when doing vaginal examination?
Cytology sample
Bacterial sample
What three things should warrant further investigation and treatment upon vaginal examination at first show to teaser?
Urovagina
Cervical discharge
Injury
What should be screened for if cervix is relaxed during first show to teaser?
Acute endometritis
What should be done if acute endometritis is present at first show to teaser?
Treat uterus with 3 day course
Re-examine next oestrus
Describe how to examine the ovaries and uterus during first show to teaser
Rectal palpation - ovarian follicular size, ovarian follicular consistency, ovarian follicular position, uterine size, uterine consistency, uterine homogeneity
Ultrasound - ovarian follicle size, shape and deformability, copora haemorrhagica and lutea, uterine size, wall thickness and fold oedema, lumenal fluid, quantity and echogenicity, pregnancy or foreign bodies
How often should ovarian and uterine examinations be done and until when?
Repeat examinations every 24-48 hours
Continue until ovulation can be predicted and mating recommended
Where do mares ovulate through?
Ovulation fossa
What should we think of when assessing follicles in mares?
Plums - tense follicle unripe plum that never ripen, good texture means a tense-soft follicle that will be ready in a few days, soft follicles like ripe plums so ready for mating
What would a follicle feel that should ovulate the next morning?
Less than 3cm
Tenst-soft to soft
Where does fertilisation occur in the mare?
Fallopian tubes
Describe a mare that is ready to ovulate
Well in oestrus when teasing Cervix relaxed, pink and moist Soft, deformable, >3cm diameter follicle Follicle migrating towards ovulation fossa Uterus losing fold oedema
When should we aim to mate a mare that we predict ovulation is about to occur in?
On day when ovulation will occur the night before
How many matings should we aim for per oestrus period?
One - minimise uterine challnge, minimise stallion ejaculations, hCG or GnRH implants/injections to achieve this
Describe the examination carried out 48 hours after mating
Rectal - loss of ovarian follicle, pain/discomfort
Ultrasound - ovarian corpus haemorrhagicum, lumenal fluid, quantity and echogenicity
What should be done if no ovulation 48 hours after mating?
Repeat mating
How should the uterus be treated if there is excessive/turbid uterine fluid 48 hours after mating?
3l sterile saline flush
1g ceftiofur sodium iu
25 iu oxytocin iv
When should you carry out an early pregnancy examination?
15-16 days
14 days at earliest
Describe a vaginal examination during early pregnancy
Cervix relaxed, pink and moist - returning into oestrus, take endometrial swab and smear, prepare for mating again
Cervix tight, pale and dry - dioestrus or pregnant
Describe a uterine palpation during an early pregnancy examination
Uteris very tonic
Sometimes perceptible bulge
Describe an ultrasound scan during an early pregnancy examination
Signs of single or multiple pregnancy - repeat examinations at 25-30, 42 days, look for live foetus, multiple pregnancy or early pregnancy failure
What should be done if persistent dioestrus is suspected on an ultrasound scan?
PGF2alpha injection after repeat examination at 48 hours
How many foals can a mare carry to term successfully?
Only one - endometrium can’t manage twins
What should be done if pregnancy failure is confirmed?
Evacuate uterus with PGF2 alpha, large volume saline and antibiotic irrigations
Submit initial flushings for investigations
Differentiate septic from non-septic causes
Describe what should be done with pregnant mares
Routine vaccinations and anthelmentic treatments
Minimal veterinary intervention until foaling
Only intervene if illness, injury or abortion occurs unless high risk pregnancy
What happens with a mares udder close to full term?
Waxing-up - enlarges, fills with colostrum, develops a waxy secretion at tips of teats
What should be done when early signs of foaling develop?
Observe discretely
Observe in a large, well-bedded, well-lit, warm foaling box
When does the first stage of labour usually occur?
Evening or night
What happens during the first stage of labour in the mare?
Becomes restless
Starts ‘nest making’ - digging, re-arranging bedding
How long does the first stage of labour last in the mare?
Variable
Describe how the first stage of labour progresses
Signs of abdominal pain
Frequent passing of small quantities of urine/droppings
Wanders around box looking for comfortable place
Lie down with some apparent difficulty
Look at flanks as contractions increase pain
May roll or get up and down several times
If a mare continues rolling with no sign of foaling what is happening?
Something wrong - foal in wrong position
What is the sign that the first stage of labour has ended?
Rupture of first water bag - chorioallantois
Describe the rupture of the first water bag
Sudden large gush of fluid
Occurring without normal urination posture
Point of no return
What needs to be done with mares who’ve had Caslick’s surgery when foaling?
Episiotomy - open vulva otherwise it will become torn during birth
What needs to be done at the beginning of the second stage of labour?
Examine mare internally to check foal is in correct position - muzzle and two front feet in birth canal
Describe the second stage of labour
Begin violent abdominal straining
Unbroken smooth, pale-coloured amnion protrudes
Allantoic fluid expelled
Muzzle and two front legs emerge - one leg in front of the other
How can a mare be assisted during the second stage of labour?
Pull front legs gently one at a time
Amnion should now have been ruptured
What should have happened during the second stage of labour?
Forelegs, head and chest expelled
Describe delivery of a foal
Abdomen and hind legs expelled
Mare rests
Stud groom encourages foal to lie still while placental blood flows through umbilical cord
When cord breaks at navel should be dressed with antiseptic
What needs to be done if a mare foals standing up?
Assistance required to support foal
Support while blood is flowing through umbilical cord
Describe bonding
Once foal born mare and foal bond
Use taste and smell as well as sight
Pull round to mare’s head to encourage her to stay lying down
What can excessive interference during bonding cause?
Confusion between mare and foal
Describe the third stage of labour
Tie amnion into ball so not damaged if mare stands suddenly
Placental release usually occurs within an hour of birth
May take longer
What should the placenta of a mare look like?
Mare’s endometrium - complete with tips of both horns intact
How quickly should a foal stand up after foaling?
Within an hour
Some take longer
Should actively seek the mare
What is one of the first reflexes that a foal develops after foaling?
Suck reflex
Progresses from mare’s shoulder to find her udder and teats
Should successfully drink to gain immunoglobulins
How quickly should a foal suck to gain immunity?
Within 12 hours
What should be allowed if the weather is good?
Exercise in nursery paddock from morning after birth
Only if mare and foal are well
Describe a ‘red bag’ delivery
Placenta is thick, red and unbroken at vulval lips
Water hasn’t broken
If continues placenta expelled before foal is born
Foal at risk of asphyxiation
Placenta must be opened manually
Describe uterine inertia
Don’t progress with foaling
Weak uterine contractions
Occasionally have low blood calcium levels
Need help with oxytocin or calcium treatments
Also need manual assistance
Describe posterior presentation
May deliver without abnormality Impact delivery Constricts umbilical blood flow Deliver rapidly Resuscitate with oxygen Monitor foal for neurological problems
What should be done with a foal presenting with a foreleg back, or head back?
Keep mare standing and walking around Tongue pulled out of mare to prevent straining Epidural analgesia Vaginal lubrication - lots Repel foetus Knee, fetlock, foot Ropes Deliver when in normal posture
What should be done with a breech presentation?
Send to a hospital
Epidural analgesia
Live foetus - caesarian section
Dead foetus - caesarian section, foetotomy
What should always be done with a dead foal?
Caesarian section
Can remove normally but risk damaging mares cervix
What should be done with twins?
Differentiate legs/heads
Repel one foetus
Deliver the other
What should be done with monstrosities?
Caesarian section
Describe what should be done with pain after foaling
Immediately after foaling - normal cramps, usually resolve quickly, treatment seldom necessary
Soon after foaling - uterine artery haemorrhage, uterine rupture, colonic/caecal rupture
24-48 hours after foaling - colon torsion
Describe a uterine artery haemorrhage
Fatal haemorrhage - severe colic or collapse, very pale mucous membranes, shock
Contained haematoma - less severe colic, normal membranes, mass on rectal
What presents with a uterine rupture?
Low grade colic
Continues and progresses to shock and peritonitis
What is needed if presented with uterine rupture?
Urgent emergency surgery
Usually fatal
Describe caecocolic rupture
Low grade colic
Progresses to severe colic with shock and peritonitis
Urgent surgery seldom indicated
Invariably fatal
What should be done with a uterine prolapse soon after foaling?
Don’t mistake for placenta
Protect uterus with warm wet towels
Urgent veterinary attention required
What should be done with a retained placenta?
Tie amnion up into a ball behind mare
Gentle pull downwards towards hock
Oxytocin drips
Antibiotics and non’steroidal analgesics/anti-endotoxic doses of flunixin meglamine
Be patient
Reassure owner/manager
Collect chorioallantois
Pump in weak povidone iodine in clean warm water - expands uterus and placenta, releases microcotyledons
Don’t tear out placenta fragments unless no alternative
Daily large-volume uterine flushes
Maintain sytemic antibiotics and anti-endotoxins
Beware of laminitis
What should be done with retained microcotyledons?
Remove placenta slowly and gently
Avoid leaving microcotyledons behind
What are some examples of cervical injuries that can occur during/after foaling?
Mucosal splits - usually heal over time
Trans-os adhesions - fucidin/hydrocortisone ointment
Lacerations - surgery sometimes necessary
Incompetence - allyl-trenbolone
Describe first degree lacerations in foaling injuries
Small tears of mucous membrane - vulva, vestibule
Usually heal uneventfully or with minimal surgical interference
Describe second degree lacerations in foaling injuries
Involve deeper structures - constrictor vulva muscle, perineal body
Require surgical correction - immediate or next day, wait for mucosal healing
Describe third degree lacerations in foaling injuries
Tearing of the: vestibular and vaginal walls, perineal body, anal sphincter, rectal wall
Require surgical correction - immediate first aid, regular cleaning to mucosal healing, surgical reconstruction
